In order to prepare a project cost estimate using our estimator, you will first need to do a little preparatory work to ensure that the pricing model understands what it is you wish to build.

In order to get a price which represents the work that needs to be undertaken you will need to know:

The dimensions in metres of any buildings which need to be demolished to make way for the new building

The number of trees or large bushes which will need to be removed to enable construction to take place

The dimensions of the new building's external wall in metres, together with the length of the join on to the current building. We always work on the principle that the length of an extension is the dimension that runs parallel to the join onto the existing building whilst the width is the other dimension at right angles to the join. The diagrams should help you understand this concept.

The number of stories for the extension - at present the pricing model can cope with extensions which are single storey and two storey, assuming the upper floor is the same size as the ground floor. We will shortly be adding the ability to price up different sized upper/lower storeys, first floor extensions over existing ground floor buildings and loft extensions.

The number of new rooms to be created on each floor. Suppose you are building an extension like the lower diagram, where the ground floor living room is being extended. In this case there is no new room being created, so on the ground floor the number of new rooms being created is zero. However, if you are adding an en-suite bathroom on the first floor, in the new space created, then the number of additional rooms upstairs is one.

The number of upper floor dormer windows being added.

Whether your new external walls are to be constructed in brick or as block walls which are then either rendered and painted or tile-hung.

What type of roofing detail you will need - any hip ends or gable ends.
A Gable end is where two opposite roof planes meet along a ridge with the third face being made up with perpendicular blockwork. A Hip End is where two opposite planes are joined by a third inclined plane of tiles.

And finally you will need to know what types of rooms you are proposing to build - any kitchens, toilets or bathrooms (which, of course, need special fixtures, wiring and plumbing).

We suggest that you get all this information together before you start using the Estimator.

But don't worry, there are helpful hints in the estimator to make sure that you get the information in correctly.

A dormer window is a window built out of a roof with its own walls and roof. Hip and Gable ends are shown below.